Telecommunications and telephony network

ABSTRACT

An integrated telecommunications and telephony network (AT), which is independent from the conventional service companies, and can guarantee global connectivity (geographical, vocal, data, fax, video, points of access for dedicated mobile devices. Internet access) between users of the same network as well as with users of networks which belong to other mobile or fixed telephony service companies, comprising a network structure which is controlled in accordance with an IP protocol (Internet Protocol), which guarantees the connectivity between the different local exchanges (CL) and local residents&#39; exchanges, whereas at local level the user has standard telephone numeration available in order to access the service; the local user accesses the local exchanges (CL) by means of bi-directional satellite stations and/or sites.

The present invention relates to an integrated telecommunications andtelephony network, and in particular to an integrated video telephony,telephony, data transmission and Internet network, by means ofbidirectional satellite stations/sites.

More specifically, the method for satellite transport of a bidirectionaltype according to the invention uses the IP protocol and is applicableto two types of networks:

-   -   1) “Full-mesh network, by means of which each user terminal can        be connected to any other terminal by means of a single        satellite jump (first terminal—satellite—second terminal) and in        which the user terminals which are associated with this        “full-mesh network” are grouped into a “Virtual Private        Network”;    -   2) “Star network”, which is used to connect user terminals and        can be connected to any other terminal by means of a double        satellite jump (first terminal—satellite—centralised satellite        hub—satellite—second terminal) and in which, in this network        configuration also, the user terminals are grouped into a        “Virtual Private Network”.

It can thus be seen that it is possible to connect in a bidirectionalmanner user terminals which are located in any part of the world bymeans of satellite connections, without having to use any longer theland connection known as the “last mile”.

For the purposes of the invention, in the present description, userterminals complete with a satellite .antenna must also be considered tobe all the embodiments implemented on mobile means such as motorised ortowed mobile land vehicles, ships and aircraft (in these last two casesuse will also be made of automatically aimed antennae which arestabilised on three axes).

Finally, in terms of band, there is a range from 64 Kbit/s to 34 Mbit/sand the services which are supported can consist of various majorapplications, such as video conferences, video telephony,compressed-mode telephony, data transmission and accessibility to theInternet network.

The normal telecommunications systems which are currently operative forfixed telephony briefly include the following: a physical system forcollection from the client to the first switching exchange, a series ofsystems for distribution of the physical connections between the clientand the exchange, such as, for example, to assure prompt determinationof faulty cables, and interchangeability of the utterances of the clientin relation to the exchange, a series of switching systems, and thetransport systems.

However, the traffic is always collected by means of physicalconnections, which usually include copper carrier cables leading fromthe location of the client to the first switching location (exchange).

Similarly, the transport systems also use carriers which are made ofcopper, or use radio bridges with a carrier frequency, or with opticalfibres.

Thus, in the conventional telecommunications systems for public use, inorder to allow broad-band services to reach the location of the client,it is necessary to use optical fibres or physical cables of a balancedor coaxial type; furthermore, the transport by radio is always carriedout with fixed-carrier consolidated technologies.

In addition, as far as GSM telephony systems in particular areconcerned, in relation to so-called international roaming, the presentsituation is particularly critical, especially from the point of view ofthe operators, since, firstly, no operator can have direct control overcosts incurred by the client during roaming conversations; this limitsconsiderably the inputs of any telephone operator.

In addition, it is not possible for the operators themselves to offerpre-paid cards to clients who make roaming telephone calls.

Finally, the telephone costs of these conversations are always tooexpensive for the clients, and it is also extremely difficult to accessthe various voice-mail facilities activated by the users.

Within the context of the requirements previously described, the objectof the present invention is to eliminate the aforementioneddisadvantages, by providing a telecommunications and telephony networkwhich guarantees geographical connection, bidirectional satellite loop,or connection of the “last mile”, points of access for dedicated mobiledevices, global connectivity between the users of the same network, aswell as with users of networks which belong to other mobile or fixedtelephony service companies, and integrated connectivity withconnections of a satellite type.

The technological innovation of the present invention in comparison withthe existing systems which use satellite routers is to permittransparent transport of data flows (for example of type E1 at 2 Mbit/swith a G.703/G.704 interface) which are not oriented to the connectionby means of satellite routers, which are necessarily oriented to theconnection.

This makes it possible to transport transparently the so-called junctionconnections, comprising in the data flow both the signals between thenetwork nodes and the voice frames between the public telephoneswitching exchanges at any hierarchical network level, base radiostations and corresponding control stations for mobile telephony systemsand private (PBX) and public switching exchanges.

Thus, owing to the numerable E1 interfaces present on the satelliterouter, the connection can be of the point-to-point type rather than ofthe point-to-muilti-point type, with considerable advantages in terms ofeconomy of scale.

Specific applications of this technological innovation with satelliteconnectivity are associated both with use for TETRA Base Stations (TBS),with the Digital Exchange systems (DXT) of the TETRA network, and withthe networks (GSM) between the Radio Base Station (RBS) and thecorresponding Base Station Control (BSC); further applications includedata transport on standard UMTS and MMS networks.

In these applications the flows at 2 Mbit/s of the E1 type with astructured G.703/G.704 interface are transported in bidirectional mode.

In practice the technological innovation is based on a satellite routerof which both the software and hardware have been modifiedcorrespondingly, which permits transparent transport of the data flowsto be joined to the router itself in transmission and in reception; theidea is to provide by means of bidirectional satellite connection thepossibility of transporting the data flows with speeds of between 2Mbit/s and 34 Mbit/s for the interconnection of public and privateswitching systems.

Another object of the present invention is to provide an integratedtelecommunications and telephony network which guarantees completevocal, data, fax and video connectivity, and points of access for mobiletelephony and Internet access.

Another object of the present invention is to provide atelecommunications and telephony network which enables the telephoneoperator to have complete control over the costs of the calls and overthe telephone traffic generated by the users in international roaming,also guaranteeing the possibility of offering pre-paid telephone trafficand prices which are lower than those applicable hitherto.

A further object of the present invention is to provide atelecommunications and telephony network which makes it possible toobtain new financial inputs, both for the telephone operators and forthe companies which are partners of the roaming operators.

Another object of the invention consists of providing atelecommunications and telephony network which uses techniques andcomponents which are normally used in the conventional systems fortransport of signals, and which has a substantially simple design and iseconomical to implement as an investment, owing to the advantagesobtained.

These and other advantages according to the present invention areachieved by providing a telecommunications and telephony network, asdescribed in claim 1, to which reference is made for the sake ofbrevity.

Other characteristics of the present invention are also defined in thesuccessive claims. Advantageously, the network according to theinvention is designed for use within the context of fixed telephonyand/or video telephony, however without excluding mobile/fixedintegration.

In particular, for the connection of the “last mile”, it uses abidirectional satellite radio bridge and a bidirectional satellitestation/site which is connected by means of the wiring of the buildingvertically to an IP video telephone.

Unlike the conventional systems which are operative at present, thetelecommunications and telephony system according to the inventioncollects the traffic by providing, depending on the cases and also inthe specific case of fixed telephony, only small lengths of copper cablefrom the client base to the roof itself of the client base, where thereis present a first network device with collection functions; the clientbase can therefore be reached directly by radio by by means of deviceswhich communicate between the client baseband the roof of the base, asin the case of mobile or cordless telephone devices; the transport iscarried out by bidirectional satellite radio bridges.

The network according to the invention also transports broad-bandintegrated services digitally via satellite, directly to the clientbase, as well as the normal fixed telephony services.

Use is also made of low emission power levels (normally lower than 20 Wfor each individual device); which however, owing to the orientation ofthe antenna, which is disposed at an elevation of 30-40°, create verylow levels of electro-magnetic field on the horizontal plane.

This involves use of a considerable number of stations, which howevercan be self-supplied, by means of the installation of small solar panels(owing to the low power levels used).

The fact of using low power levels has another clear advantage,consisting of the very low level of electromagnetic pollution.

The system also guarantees vocal, data, fax and video connectivity, andpoints of access for mobile telephony, Internet access and videotelephony.

The central core of the network, which guarantees connectivity betweenthe various local exchanges and local residents' exchanges, is based onan IP (Internet Protocol) network structure, whereas at local level, theuser has standard telephone numeration available in order to access theservice.

At the level of the local exchange, there is transformation, which istransparent to the user, of routing based on standard telephonenumeration, into routing based on the IP protocol, and similarlytransformation of the digital or analogue signal (which contains thevocal, fax, data etc information), into data packages which are based onthe IP protocol; in addition, in order to guarantee greater connectivitybetween the various resources, at a lower cost than in the knownsolutions, algorithms for compression of the information are applied.

As previously stated, the local user accesses the local telephoneexchanges by means of bidirectional satellite radio bridges orstations/site; at the level of the local exchange, the telephonic flowsobtained from various local radio bridges are incorporated, compressedand digitised, such that they can be transmitted on a network which isbased on IP protocol, produced by means of connection on bidirectionalsatellite radio bridges, for connection at the level of local residents(between district exchanges), and with a satellite radio carrier, orusing other technologies, for connection between different towns.

Finally, the system according to the invention provides a fixedtelephony network, comprising various contents with added value, whichis completely independent from the conventional service companies, andfrom the physical carriers which are used as standard by the latter forthe creation of a complete telephony network.

Connectivity is guaranteed completely between users of the same networkin a local, local resident, regional, national and supranationalenvironment, as well as between users of networks of other servicecompanies.

The system according to the invention can also control all the flows ofinformation and data which are currently available on conventionaltelephony networks (local calls, fax, data and video transmission, videotelephony and video conferences, Internet access, points of access formobile telephony).

In particular, the video telephony systems are supported by appropriatedevices which use the IP protocol at connection level, such that thevideo telephony itself can occupy a band of between 128 Kbit/s and 384Kbit/s.

The system in question also transports a plurality of services in asingle duct, thus enabling the control operator to avoid having to use aplurality of physical means in order to offer different services.

Finally, the system can be installed quickly and easily, since it doesnot require excavation work, with all the consequent potential problems(permits, passage through historic town centres, any damage, etc), it ismore economical than the conventional systems, owing to the limitedpower levels of the devices and the relative simplicity of the networkarchitecture, and has considerable flexibility and simplicity of use forthe network operator, which can also control and manage the entiresystem from several points, or from a single national node.

Further characteristics and advantages of a telecommunications andtelephony network according to the present invention will become moreapparent from the following description, provided by way of non-limitingexample with reference to the attached drawings, in which:

FIG. 1 illustrates schematically a method according to the presentinvention, for connection of local accesses of fixed telephone devices,to a telecommunications and telephony network;

FIG. 2 represents schematically a method according to the presentinvention, for connection of local accesses of cellular telephonedevices to a telecommunications and telephony network;

FIG. 3 represents a block diagram of a telecommunications and telephonynetwork according to the invention, connected to telephone networks forlocal residents; and

FIG. 4 illustrates schematically an example of global connection to thevarious local accesses of a telecommunications and telephony network forlocal residents, according to the present invention.

With particular reference to FIG. 1, it can be seen that thearchitecture of the network according to the invention is based ondifferent levels, subdivided hierarchically, wherein the lowest levelscomprise a first series of connections, indicated as CO, Cl, of thelocal users UL of a local access AL to local centralising devices MD,and of the said local centralising devices MD to the local exchange GV:these connections are formed mainly by means of data flows of the typeE1, at 2 Mbit at least.

The highest levels, relative to the connections C2 between the localexchanges GV, the local residents' exchanges, regional and nationalexchanges, and the nodes for access to the networks of other servicecompanies AG, are connected by means of data flows which are organisedaccording to the protocol TCP/IP.

At the highest levels, the fixed telephony network AT according to theinvention is based on a conventional IP (Internet Protocol) structure,on which the standard telephony is transformed into telephony of the“Over IP” type.

One of the main innovative aspects of the network which is the subjectof the present invention is the use, in most or all of the connections,of connections C1, C2 of the bidirectional satellite type, which arediversified according to the level of the network through which thesignal is passing.

The only portion of connection based on physical carriers which are notof the radio type, is the connection, indicated as CO, between the finaluser UL (telephone or analogue modem) and the local centralising deviceMD, which consists of a multiplexer/demultiplexer, which generates aflow E1 with 2 Mbits, standard G.703/HDB3; in fact, this connection isnormally formed with cabling by means of a telephone pair or opticalfibres.

The local centralising device MD is normally always present in the samestable unit as the final user, and can incorporate up to a minimum of 30telephone calls simultaneously.

If required, the final user can be connected to the multiplexer by meansof one or a plurality of lines, or can activate a connection of the ISDNtype, with a minimum of 64 Kb, or a variable or fixed band dataconnection, according to the capacity required at that moment fortransport of the video, audio or data flow.

As an alternative to the conventional fixed telephony connection, it ispossible in addition to create a series of points of input (localaccesses indicated by AL1) to the telephony network AT, according to theinvention, for telephone devices of the cellular or cordless type TC.

Usually, the cover for cordless or mobile telephone devices TCguarantees an environment which is restricted to the building or to thearea adjacent to the building itself, although greater cover is notexcluded if the area of the final user is well covered by radio cellsCR.

The signals C4 received by the radio cells CR are in digital format, andare obtained from the mobile telephone devices TC; in this respect, seealso the diagram in FIG. 2.

At the output of the cells CR, there is present a digital flow,indicated as C41, of standard type G.703/HDB3, with 2 Mbits.

One or a plurality of flows with 2 Mbits, of the type indicated as C41and obtained from the cells CR, are sent to a compression and conversiondevice GV (gateway), which compresses and converts signals C41 into IPprotocol.

At the output of the device GV, the 2 Mbit signal in IP, which isindicated as C5 in FIG. 2, is sent to a router R; the router R addressesthe various signal packages in the required directions, in accordancewith a configuration which is decided by the network service company.

Thus, downstream from the device R, the signal C6 can, for example,equally well be conveyed to a bidirectional satellite connection ST, orit can be transmitted to another point on the telephony network AT.

The connection between the different points of the network AT can takeplace on a single-hop basis (direct connection between the localcentralising device MD and the local exchange) or on a multi-hop basis(connection carried out by means of intermediate repeaters between thelocal centralising device MD and the local exchange).

Leading to the local exchange CL there are one or a plurality of dataflows E1, with 2 Mbit of standard G.703, indicated as C7 in FIG. 2,which are obtained from one or a plurality of local centralising devicesMD, or from accesses to the networks of other service companies AG,based on data flows of standard SS7 (indicated as C8 in FIG. 2), singleconnections with local users, by means of pairs or optical fibres, andpoints of access for mobile telephony.

At the level of the local exchange CL, the standard telephone flow isconverted into a flow according to the IP protocol, and the highestlevels of the network AT, which guarantee the connection between thelocal exchanges CL, the exchanges for local residents, regional andnational exchanges, and the nodes C2 for access to the networks of otherservice companies, are organised as a standard network of the type withIP protocol.

In order to implement this type of telephony, it is thus necessary totransform the information, whether it is in the form of voice, fax,video or data, in whatever format it reaches the local exchange CL (flowE1 with 2 Mbits, standard G.703, single digital or analogue signal, SS7data flow) into a flow of homogeneous data, such as to be transported ona network with a package based on the standard protocol TCP/IP (Internetstandard protocol); in addition, it is necessary to transform theprocess of routing telephone calls based on telephone numerationspecific to the telephone networks, by replacing the standard telephonenumeration, at network level, by addresses according to the IP protocol.

This process is altogether transparent at levels of local use, and isimplemented by means of an applicative programme for control of thenetwork.

The device which controls the conversion is the conversion andcompression device GV, which in practice consists of a multi-protocolgateway device.

Each local exchange CL is equipped with at least one device forconversion and compression GV, which thus processes different types ofinputs (for example one or a plurality of flows E1 G.703, one or aplurality of single digital or analogue signals in multi-protocol,whilst distinguishing one from another, or one or a plurality of dataflows SS7), and transforms them into data packages based on the standardprotocol TCP/IP.

At the same time, it converts the standard numeration into addressing ofthe IP type, and controls the transmission of correctly addressedpackages on the high hierarchical levels of the AT network, in IPprotocol.

The conversion device GV also permits the opposite passage, and thusconversion of the data flows in IP standard (high hierarchical levels ofthe AT network) into the data flows sent to the local user, or to usersof networks of other service companies (transformation into flow E1,standard G.703, into a single digital or analogue signal, into SS7 dataflows, etc).

In addition, since it can obtain digital data, by implementingalgorithms for compression both of the vocal information and of theaddressing in the IP protocol, the device GV makes it possible to obtaina reduction of the programmable and variable data flows which is up to10 times the nominal level (compression ratio of 10:1). This involves afurther saving in infrastructures, leading to telephone charges whichare far more advantageous for the user.

At the level of the local exchange CL, the local residents' exchange andthe regional exchange, control of telephone charges is also provided, inthe sense that each exchange is autonomous in calculating the charges tothe users which are directly connected to it; the bill may or may notthen be sent to one or a plurality of accounting collection centres,which subsequently control and collect the payments.

To summarise, the device GV permits transformation of the standardtelephone flow which enters a data flow in compressed IP protocol,permits transformation of the process of standard telephone routing intoIP protocol routing, and guarantees control of the telephone charges,and transformation of the flow of data in compressed IP protocol into astandard telephone flow output.

The data flows in IP protocol which are output from the conversiondevices GV must be routed on a network which is based on IP protocol,and thus, each device GV is connected directly to a local routing deviceR in IP protocol, by means of a 10/100 data flow BaseT.

In the network topology in IP protocol, the device GV represents agateway device for local access or access outside the network AT.

The telecommunications and telephony network AT according to theinvention, at IP protocol level, consists of various hierarchicallevels, which are subdivided into a local network (district), localresidents' network, regional network, national network, andsupranational network.

Routing within the network AT is controlled directly by the dedicateddevices, indicated as R, in IP protocol, which are connected to thelocal compression devices GV, or to satellite routing devices RS, or toradio bridges PR, which permit interconnection between networks RLC atthe level of local residents (in this respect see the diagram in FIG.3); in particular, at the level of local residents, the data flow outputfrom the routing device R is sent to the other routing devices R, mainlyvia a connection, indicated as RLD, with bidirectional satellite radiobridge technology, in frequency bands which are dependent on the countryin which the network AT is operating (in this case also, the connectioncan take place directly or by means of intermediate repeaters).

At the level beyond that of local residents (connections betweendifferent towns or regional locations), the connection can also takeplace with conventional systems, such as optical fibres, coaxial cables,radio bridges or the like, but it takes place mainly by means of asatellite connection node ST (geostationary satellite), wherein therouting device R is connected to the satellite transmission device witha data flow of 10/100 BaseT.

The satellite connection ST has a capacity which is variable accordingto the traffic required by the network AT that moment, starting from aminimum of 64 Kbits; for greater traffic demands it is possible to use aplurality of segments with a spatial capacity, placing them in parallel.

Taking into consideration that the network AT must form a privatetelephone network, in practice it is possible to structure ahierarchical level, which, in a national reference network node, hasaccess to the outside world; in this case, the access to the outsideworld guarantees the possibility that a user of the network AT can reacha user who is not connected to the network AT, and thus, a client ofanother telephony operator.

Starting from the national reference network node, a structure on aplurality of hierarchical levels is produced, which can reach theindividual user of the network AT in every geographical area ofdifferent countries.

At the level of the national reference node, in addition, there iscontrol of the connections between the regional nodes of the network AT,as well as control of the telephone charges; the connection between thenational reference node and the regional nodes is provided by means of asatellite network VSAT, or more generally by means of a satelite networkwhich operates digitally, and is preferably of the geostationary type.

The regional node of the network AT guarantees the connection betweenthe various local resident nodes located in the region; at this level,transit takes place of all the calls between users of the network AT,which are directed to local resident areas in the same region, otherthan the local resident area of origin, or those which are directed toother regions or to other telephone operators.

The connection between the regional node and the local resident nodes isalways produced digitally, by means of bidirectional satellite radio,transmission, or, if this is not possible, by means of communication viaoptical fibres.

A regional router routes the communications between the various localresidents' networks RLC, or creates the connection with the otherregional networks by means of the satellite network VSAT; all thesignals are of the digital type.

The local residents' network, which is indicated as RLC in FIG. 3,assures the telephone connections or calls between users of the networkAT in the same town, which are controlled locally by means of thestructure schematised in FIG. 4.

Each town is subdivided into geographical areas with variabledimensions, with a maximum radius of approximately 3 Km, known as“sub-local resident areas”; each individual “sub-local resident” area isin fact a local point of access AL, AL1 to the network AT in IPprotocol, since, in fact, it is at this level that the standardtelephony calls are transformed into IP protocol telephony.

Each individual area is provided with a conversion and compressiondevice GV, which guarantees the access and initial routing on thenetwork AT; taking into consideration the compression properties of thegateway devices GV, it is possible to connect to each access node AL,AL1, up to 300 simultaneous standard vocal telephone connections or dataconnections, each of which is up to 2 Mbits.

The connection between the access node AL, AL1 and the standardtelephony systems (of the PABX type) is provided by means ofbidirectional satellite radio bridges or via optical fibres.

In order to assure the connection between the access nodes AL, AL1, eachaccess node AL, AL1 is provided with a routing device; in addition, anaccess node AL, AL1 also provides the connectivity with the regionalnode, in order to permit the connection between the individual localresidents' networks.

The physical connection between the various access nodes AL, AL1, isprovided with bidirectional satellite digital radio bridges or onoptical fibres, whereas, the network topology must be designed locallyin order to minimise the costs, whilst maximising the local residentcover.

Finally, the use of the routing devices assures redundancy of thenetwork structures.

The description provided makes apparent the characteristics andadvantages of the telecommunication and telephony network which is thesubject of the present invention.

To summarise, these consist of:

-   -   scalability, i.e. enlargement of the radio band, simply by        adding one or a plurality of bidirectional satellite radio        bridges and the corresponding antenna system, on every site        where this is necessary;    -   very low volume of power emitted by the radio systems, which can        thus also be self-supplied by means of solar panels;    -   increased services offered on a single physical carrier, in        comparison with conventional telecommunications systems;    -   ease and speed of installation, and high level of economic        viability in production and use;    -   possibility of transporting any digital signal, and of carrying        out A/D and D/A conversions;    -   possibility of compressing the telephone signal, with consequent        optimisation of the network resources;    -   complete control of the network from a single location or        national node;    -   complete integration between fixed telephony and mobile        telephony;    -   simplicity in implementation of the connection between the Radio        Base Station (TBS or RBS) and Control Station (DXT or BSC),        which eliminates the difficulties caused by laying cables for        implementation of the flows at 2 Mbit/s;    -   possibility of using simply and quickly Radio Base Stations (TBS        or RBS) to be located at the appropriate time in places where        there is an immediate need for cover, such as putting into        service a Radio Station in order to increase the number of        carriers in the event of festivals, conventions, etc., and        possibility of providing cover by means of transportable Radio        Stations in locations which have sustained disasters of any        type; and    -   simple interfaceability of the system with the pre-existing        systems.

Finally, it is apparent that many variants can be made to thetelecommunications and telephony network in question, without departingfrom the principles of novelty which are inherent in the inventiveconcept, and it is also apparent that, in the practical implementationof the invention, the details illustrated can be used in any form,according to requirements, and can be replaced by others which aretechnically equivalent.

1. Telecommunications and telephony network (AT) for controlling mobile(TC) or fixed peripheral devices at a customer premises, of the typecomprising at least one local area network, at least one localresidents' network (RLC), at least one regional network, at least onenational network and a central network, said telecommunications andtelephony network (AT) being provided for delivering signals and databetween a plurality of local accesses (AL, AL1), including local users(UL), and a plurality of networks accesses (AG), through local exchanges(CL, CR), each of said local exchanges (CL, CR) including amulti-protocol gateway device (GV) for video and audio signals and datacompression and conversion into IP packets bearing IP telephony dataflow or data flow from the Internet and a local routing device (R) forrouting said IP telephony data flow or data flow from the Internet,wherein said local users (UL) of each local access (AL, AL1) areconnected to local centralising devices (MD) through first linking means(CO) for flowing data and signals, and said local centralising devices(MD) are in turn connected to said local exchanges (CL, CR) throughsecond linking means (C1, C4) for flowing data and signals, while saidlocal exchanges (CL, CR) are connected to said networks accesses (AG)through third linking means (C2, C41) for flowing data and signals,characterised in that at least said second (C1, C4) and said thirdlinking means (C2, C41) are constituted by bidirectional satellite radiobridges (RLD, ST).
 2. Telecommunications and telephony network (AT) asclaimed in claim 1, characterised in that said first linking means (CO)are constituted by physical cables, such as telephone twisted pairs oroptical fibers.
 3. Telecommunications and telephony network (AT) asclaimed in claim 1, characterised in that said local routing devices (R)are connected to satellite routing devices (RS) or to radio bridges(PR), said radio bridges (PR) being able to provide connection betweenlocal residents' networks (RLC).
 4. Telecommunications and telephonynetwork (AT) as claimed in claim 1, characterised in that each nationalnetwork is connected to the relative regional network by means of adigital geostationary satellite network.
 5. Telecommunications andtelephony network (AT) as claimed in claim 1, characterised in that eachregional network is connected to the relative local residents' network(RLC) by means of a digital bidirectional satellite radio transmissionor by means of communication via optical fibres.